Various types of image-forming devices have been developed for forming images on a recording medium. One such conventional image-forming device includes a developing device that deposits toner onto electrostatic latent images to develop the latent images into toner images, and a toner cartridge that is mounted in the developing device for accommodating toner in a casing and supplying the toner to the developing device. This type of image-forming device forms images by transferring the toner images developed by the developing device onto the recording medium.
One of these image-forming devices disclosed in United States Patent Application Publication No. US 2004/134560 A1 includes a toner cartridge mounted in a developing device, which toner cartridge includes a cylindrical casing having a first opening formed in the outer peripheral surface thereof for discharging the toner; and a cylindrical slide cover covering the outer peripheral surface of the casing and having a second opening formed therein for exposing the first opening when positioned opposite the same.
In order to mount the toner cartridge in the developing device, the user holds the slide cover of the toner cartridge with one hand and exposes the first opening of the toner cartridge by rotating the casing of the toner cartridge with the other hand until the first opening is positioned opposite the second opening. When removing the toner cartridge from the developing device, the user holds the slide cover of the toner cartridge with one hand and closes the first opening in the toner cartridge with the other hand by rotating the casing of the toner cartridge until the first opening no longer opposes the second opening.